Collisionless

Collisionless may refer to:


 * In information theory and computer science, computer networking architectures where collisions between packets of data cannot occur
 * In computer science, situations where collisions, or occurrences of the same value, cannot occur in a structure (and prevent reliable lookups)
 * In cosmology and physics, a medium in which the interaction cross-section between particles is so low that collisions between particles have no significant effect on the system. See Shock waves in astrophysics.